Particulates and coal

Particulate matter (PM), also known as particle pollution, includes the tiny particles of fly ash and dust that are expelled from coal-burning power plants. Particulate pollution is a mixture of soot, smoke, and tiny particles formed in the atmosphere from sulfur dioxide (SO2), nitrogen oxides (NOx) and ammonia (NH3). Fine particles are a mixture of a variety of different compounds and pollutants that originate primarily from combustion sources such as power plants, but also diesel trucks and buses, cars, etc. They are sometimes referred to as PM2.5 (particulate matter smaller than 2.5 microns in diameter - less than one-hundredth of the width of a human hair). Fine particles are either emitted directly from these combustion sources or are formed in the atmosphere through complex oxidation reactions involving gases, such as sulfur dioxide (SO2) or nitrogen oxides (NOX). Among particles, fine particles are of gravest concern because they are so tiny that they can be inhaled deeply, thus evading the human lungs' natural defenses.

U.S. Regulations
In 1923, the first electrostatic precipitator was employed in a coal plant, which used electrical fields to remove particulate matter from a boiler's flue gas, like static electricity causing dust to cling to certain types of materials. Electrostatic precipitators, along with baghouses (which work like large industrial-scale vacuum cleaners to capture ash and dust particles in felt or woven fabric bags), have been used to reduce the release of soot-forming particulate matter, but some still escapes, leading to negative health effects.

The EPA Office of Air Quality Planning and Standards (OAQPS) has set National Ambient Air Quality Standards under the Clean Air Act for six principal pollutants, which are called "criteria" pollutants: sulfur dioxide, particulate matter, nitrogen oxides, ozone, lead, and carbon monoxide. After the EPA sets or revises each standard and a timeline for implementation, the responsibility for meeting the standard falls to the states. Each state must submit an EPA-approved plan that shows how it will meet the standards and deadlines. These state plans are known as State Implementation Plans (SIPs)."

Since 1997 coarse (diameter greater than 2.5 μm) and fine (diameter between 0.1 μm and 2.5 μm) particles have been regulated by the EPA, but ultrafine particles (diameter less than 0.1 μm) remain unregulated. Roughly 80% of the ash falls into an ash hopper, but the rest of the ash then gets carried into the atmosphere to become fly ash.

In a motion filed on December 7, 2010, the EPA asked for an extension in the current court-ordered schedule for issuing rules that would reduce harmful air emissions from large and small boilers and solid waste incinerators, which would cut emissions of pollutants, including mercury and soot. EPA is under a current court order to issue final rules on January 16, 2011 and is seeking in its motion to the court to extend the schedule to finalize the rules by April 2012. The agency said the additional time is needed "to re-propose the rules based on a full assessment of information received since the rules were proposed."

March 2011: New EPA Standards for Mercury and Air Toxics Proposed
On March 16, 2011, the U.S. Environmental Protection Agency (EPA) announced its proposed emissions standards to limit mercury, acid gases and other toxic pollution from power plants. The EPA estimates that there are approximately 1,350 units affected by the action, including 1,200 existing coal-fired units.

There are currently no existing national limits on the amount of mercury and other toxic air pollution released from power plant smokestacks. The 1990 Clean Air Act Amendments mandated EPA control toxic air pollutants, and the EPA took action to reduce mercury emissions from the highest-emitting sources, except power plants, as the Clean Air Mercury Rule passed under President George W. Bush was vacated by a court.

The proposed toxics rule would reduce emissions of heavy metals, including mercury (Hg), arsenic, chromium, and nickel, and acid gases, including hydrogen chloride (HCl) and hydrogen fluoride (HF). EPA is also proposing to revise the New Source Review performance standards (NSPS) for fossil-fuel-fired plants. This NSPS would revise the standards new coal- and oil-fired power plants must meet for particulate matter (PM), sulfur dioxide (SO2), and nitrogen oxides (NOx). The proposed standards should reduce mercury emissions from power plants burning coal and oil by 91 percent, acid gas pollution by 91 percent, direct particulate matter emissions by 30 percent, and sulfur dioxide (SO2) emissions by 53 percent, down to 2.1 million tons of annual SO2 emissions.

The EPA's proposed standards are projected to save as many as 17,000 lives every year by 2015; prevent up to 120,000 cases of childhood asthma symptoms and 11,000 fewer cases of acute bronchitis among children every year; avoid more than 12,000 emergency room and hospital visits annually; and prevent 850,000 lost work days every year. The monetized benefits from the improved health standards are estimated to be $59 billion to $140 billion annually, compared to annual compliance costs of approximately $10.9 billion. The EPA also projects that the proposed standards will create up to 31,000 short-term construction jobs and 9,000 long-term utility jobs.

Requirements of the new standards include:
 * For all existing and new coal- and oil-fired electric utility steam generating units (EGUs), the proposed standards would establish numerical emission limits for mercury, PM, and HCl.
 * For all existing and new oil-fired EGUs, the proposed toxics rule would establish numerical emission limits for total metals, HCl, and HF.
 * Actions available to power plants to meet the emission limits include wet and dry scrubbers, dry sorbent injection systems, activated carbon injection systems, and baghouses, all part of Maximum Achievable Control Technology (MACT).
 * The proposed standards would establish work practices, instead of numerical emission limits, to limit emissions of organic air toxics, including dioxin/furan, from existing and new coal- and oil-fired power plants.
 * The proposed revisions to the NSPS would include revised numerical EGU emission limits for PM, SO2, and NOX.

Health effects
Particulate matter from coal-fired plants can be harmful and have negative health impacts. Studies have shown that exposure to particulate matter is related to an increase of respiratory and cardiac mortality. Particulate matter can irritate small airways in the lungs, which can lead to increased problems with asthma, chronic bronchitis, airway obstruction, and gas exchange. Several studies have also shown a correlation between coal-related air pollutants and stroke. In Medicare patients, ambient levels of PM2.5 have been correlated with cerebrovascular disease, and PM10 with hospital admission for ischemic stroke, which accounts for eighty-seven percent of all strokes. The size and chemical composition of these particles affects the impacts on human health.

According to a report by the Clean Air Task Force, the health effects from fine particle air pollution include death, hospitalizations, emergency room visits, asthma attacks, and a variety of lesser respiratory symptoms. Key findings include:


 * Fine particle pollution from U.S. power plants cuts short the lives of over 30,000 people each year.
 * In more polluted areas, fine particle pollution can shave several years off its victims' lives.
 * Hundreds of thousands of Americans suffer from asthma attacks, cardiac problems and upper and lower respiratory problems associated with fine particles from power plants.
 * The elderly, children, and those with respiratory disease are most severely impacted by fine particle pollution from power plants.

According to the American Lung Association, particle pollution can damage the body in ways similar to cigarette smoking, helping explain why particle pollution can cause heart attacks and strokes. However, even short-term exposure to particle pollution can kill: peaks or spikes in particle pollution can last for hours to days. Deaths can occur on the very day that particle levels are high, or within one to two months afterward.

The EPA has concluded that fine particle pollution poses serious health threats:


 * Causes early death (both short-term and long-term exposure)
 * Causes cardiovascular harm (e.g. heart attacks, strokes, heart disease, congestive heart failure)
 * Likely to cause respiratory harm (e.g. worsened asthma, worsened COPD, inflammation)
 * May cause cancer
 * May cause reproductive and developmental harm

A 2010 yearlong Pittsburgh Post-Gazette investigation found that Allegheny and Westmoreland counties and the rest of southwestern Pennsylvania - which are near multiple coal plants - show higher mortality rates for multiple sclerosis. The newspaper notes that studies suggest particulate matter pollution can trigger, aggravate or cause relapses of the autoimmune disease.

CO2 and particulate matter
A 2009 study, “Enhancement of Local Air Pollution by Urban CO2 Domes,” published in Environmental Science & Technology by Mark Z. Jacobson, found that domes of increased carbon dioxide concentrations – discovered to form above cities more than a decade ago – cause local temperature increases that in turn increase the amounts of local air pollutants, raising concentrations of health-damaging ground-level ozone as well as particulate matter in urban air.

According to Jacobson: "Warming increases water vapor, and both water vapor and higher temperatures increase ozone where the ozone is already high but have less effect where the ozone is low. Carbon dioxide domes over cities increase temperatures over the cities above and beyond the heat island effect, and these higher temperatures increase water vapor, and both higher water vapor and higher temperatures increase the rates of chemical air pollution production over cities relative to rural areas. The results suggest a causal nature of increased air pollution mortality due to increased carbon dioxide where the air pollution is already high. Thus, controlling CO2 emissions at the local level will reduce air pollution and the resulting air pollution mortality."

Jacobson’s estimates that “reducing local CO2 may reduce 300-1000 premature air pollution mortalities/yr in the U.S. and 50-100/yr in California, even if CO2 in adjacent regions is not controlled.”

Health costs
In 2010, Abt Associates issued a study commissioned by the Clean Air Task Force, a nonprofit research and advocacy organization, quantifying the deaths and other health effects attributable to fine particle pollution from coal-fired power plants. The study found that over 13,000 deaths and tens of thousands of cases of chronic bronchitis, acute bronchitis, asthma-related episodes and asthma-related emergency room visits, congestive heart failure, acute myocardial infarction, dysrhythmia, ischemic heart disease, chronic lung disease, peneumonia each year are attributable to fine particle pollution from U.S. coal-fired power plants. Abt assigned a value of $7,300,000 to each 2010 mortality, based on a range of government and private studies. Valuations of illnesses ranged from $52 for an asthma episode to $440,000 for a case of chronic bronchitis.

Click here to see the total estimated heath effects and costs for each U.S. coal power plant.

EPA finds Clean Air Act benefits will add up to $2 trillion by 2020, mainly from PM regulations
According to an EPA report released in March 2011, "The Benefits and Costs of the Clean Air Act from 1990 to 2020", the annual dollar value of benefits of air quality improvements from 1990 to 2020 will reach a level of approximately $2.0 trillion in 2020. The benefits would be achieved as a result of Clean Air Act Amendment-related programs and regulatory compliance actions, estimated to cost approximately $65 billion by 2020.

Most of the benefits (about 85 percent) are attributable to reductions in premature mortality associated with reductions in ambient particulate matter: "as a result, we estimate that cleaner air will, by 2020, prevent 230,000 cases of premature mortality in that year" (Introduction). The remaining benefits are roughly equally divided among three categories of human health and environmental improvement: preventing premature mortality associated with ozone exposure; preventing morbidity, including acute myocardial infarctions and chronic bronchitis; and improving the quality of ecological resources and other aspects of the environment.

According to the report: "The very wide margin between estimated benefits and costs, and the results of our uncertainty analysis, suggest that it is extremely unlikely that the monetized benefits of the CAAA over the 1990 to 2020 period reasonably could be less than its costs, under any alternative set of assumptions we can conceive. Our central benefits estimate exceeds costs by a factor of more than 30 to one, and the high benefits estimate exceeds costs by 90 times. Even the low benefits estimate exceeds costs by about three to one."

2011 American Lung Association report on health effects
In March 2011, the American Lung Association released the report, "Toxic Air: The Case for Cleaning Up Coal-fired Power Plants," on the hazardous air pollutants emitted from power plants. Key findings from the report included:


 * Coal-fired power plants produce more hazardous air pollution in the United States than any other industrial pollution sources;
 * More than 400 coal-fired power plants located in 46 states across the country release in excess of 386,000 tons of hazardous air pollutants into the atmosphere each year;
 * Particulate matter pollution from power plants is estimated to kill approximately 13,000 people a year. Most coal-fired plants are concentrated in the Midwest and Southeast.

Soot and global warming
Particulate pollution is a mixture of soot, smoke, and tiny particles formed in the atmosphere from sulfur dioxide (SO2), nitrogen oxides (NOx) and ammonia (NH3). Soot, or black carbon, is made up of tiny carbon particulate matter that contributes to global warming by absorbing heat in the atmosphere and reducing albedo, the reflection of sunlight, when deposited on snow and ice. In a paper published in May 2008 in Nature Geoscience, researchers found that black carbon soot may play a larger role than previously thought in global warming. A 2010 USAID study identified black carbon as the second or third largest contributor to the current anthropogenic global warming, surpassed only by carbon dioxide and methane.

Related SourceWatch articles

 * Air pollution from coal-fired power plants
 * Campus coal plants
 * Clean Air Act
 * Clean Air Interstate Rule
 * Clean Air Watch
 * Clean Coal Technology
 * Clean Water Act
 * Clear Skies Initiative
 * climate change / global warming
 * Climate impacts of coal plants
 * Coal
 * Coal and jobs in the United States
 * Coal and transmission
 * Coal-fired power plant capacity and generation
 * Coal moratorium
 * Coal phase-out
 * Coal plant conversion projects
 * Coal plants near residential areas
 * Coal sludge
 * Coal Studies
 * Coal waste
 * Comparative electrical generation costs
 * Dispelling the myths of the acid rain story
 * Divestment and shareholder action on coal
 * Environmental impacts of coal
 * Environmental Protection Agency
 * EPA Coal Plant Settlements
 * Existing U.S. Coal Plants
 * External costs of coal
 * Fly ash
 * Health effects of coal
 * Heavy metals and coal
 * Mercury and coal
 * New Source Review
 * Oldest existing coal plants
 * Opposition to existing coal plants
 * Radioactivity and coal
 * Retrofit vs. Phase-Out of Coal-Fired Power Plants
 * Scrubber Retrofits at Existing Coal Plants
 * Scrubbers
 * State coal subsidies
 * Sulfur dioxide and coal
 * Thermal pollution from coal plants
 * United States and coal
 * U.S. Coal Capacity by Year
 * Water consumption from coal plants

External resources

 * Particle Pollution American Lung Association.
 * "Dirty Air, Dirty Power: Mortality and Health Damage Due to Air Pollution from Power Plants," Conrad G. Schneider, Abt Associates, June 2004, sponsored by Clean Air Task Force; Synopsis
 * "Dirty Kilowatts: America’s Most Polluting Power Plants," Environmental Integrity Project, July 2007
 * "Dispelling the myths of the acid rain story (part II)," Don Munton, 7/1/98
 * "Particulate Matter Research Program," US EPA, July 2004
 * Francine Laden, Joel Schwartz, Frank E. Speizer and Douglas W. Dockery, "Reduction in fine particulate air pollution and mortality," American Journal of Respiratory and Critical Care Medicine, 2006